C# 爲TextBox增加SelectText改變事件

使用方法

 

 

  private void Form2_Load(object sender, EventArgs e)
        {
            TextBoxSelectTextChangedClass _TextSelectChanged = new TextBoxSelectTextChangedClass(textBox1);         
            _TextSelectChanged .SelectText += new EventHandler(_TextSelectChanged _SelectText);
        }

        void _TextSelectChanged _SelectText(object sender, EventArgs e)
        {
            this.Text = textBox1.SelectedText;
        }

 

 

 

下面是全部的類  需要引用 System.Windows.Forms;

 

 

        /// <summary>
        /// 爲TextBox增加Select事件
        /// qq:116149
        /// [email protected]
        /// </summary>
        public class TextBoxSelectTextChangedClass: NativeWindow
        {
          

            private TextBox m_TextBox;
         
            public TextBoxSelectTextChangedClass(TextBox p_TextBox)
            {
                if (p_TextBox == null) throw new Exception("TextBox不能爲空");
                m_TextBox = p_TextBox;
                m_SelectionStart = p_TextBox.SelectionStart;
                m_SelectionLength = p_TextBox.SelectionLength;
                base.AssignHandle(p_TextBox.Handle);
            }

            public event EventHandler SelectText;

            private int m_SelectionStart = 0;
            private int m_SelectionLength = 0;

            protected override void WndProc(ref Message m)
            {
                base.WndProc(ref m);
                if (m.Msg == 512 || m.Msg == 256 || m.Msg == 177)
                {
                    if (m_TextBox.SelectionLength != m_SelectionLength || m_SelectionStart != m_TextBox.SelectionStart)
                    {
                        m_SelectionStart = m_TextBox.SelectionStart;
                        m_SelectionLength = m_TextBox.SelectionLength;
                        if (SelectText != null) SelectText(m_TextBox, new EventArgs());
                    }
                }            
            }
        }